On 03/25/2013 10:26 AM, m.roth at 5-cent.us wrote: > Just now, over lunch, it failed... until I restarted nscd. My manager > tells me it's caching... but it seems to be caching momentary failures. That could be coincidence. As far as I know, Firefox will not use nscd for hostname lookups. I confirmed Firefox using strace, but not others. If edns0 changed your system's behavior, I would suspect that someone recently turned on DNSSEC, and it's not working correctly.